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red · Guest

Campers,
Found a fun DIY project, a while back. Maybe if somebody is long on
ability, and short on cash, it might do the trick for them.
The gadget reads out in meters, so if you're a Yank like me, multiply
everything except the beeps, times three. (Close enough, right?) :-)

http://www.qsl.net/xq2fod/Electron/Vario/vario.html

There are various chemical kits that will let you home-brew a printed
circuit board; any good electronics shop should help with that.
There are also commercial circuit board shops, who will make one etched
blank board for you, but five or ten more boards would cost very little
extra. If you can give them an exact-sized pattern to start, the price
should drop nicely. That could make this gadget a good club project for
your local wizards.
You might consider using the "excellent" chip sockets under the chips, to
make repairs easier; that's your call. All pins on chips go into round
"pads", except Pin 1 goes into a square "pad". Look for electronics
"enclosures" if you want a commercial box for the gadget, maybe from Newark
or Grainger in the USA. You will need some space in there for the
board/display, the speaker, charge jack, 9-pin data port, and 6 cells of
battery power.
The "good" electronics shops will somewhat resemble a rummage sale, but
they will have almost everything except the few trick pieces, and prices
will be very reasonable. If the place looks like a shop in a mall (with or
without the mall), then your wallet will be in for a very serious beating
there. You can get the few specialty items necessary, from the Internet.
Find a working source (and the price) for each chip, *before* you begin, if
money is scarce.
I have not built one of these, but it all looks reasonable to me.
--
Cheers,
Red
--
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Replies will bounce, unless you remove
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P.S. Not relevant, but...
Free advice, and maybe worth the price,
for new and low-time HG pilots,
at my website:
http://www.xmission.com/~red/

@(none) · Guest

Red,

I built this project a while back. It's a very reasonable project.
Had to scrap the first one because I didn't use sockets for the ICs and
I think I fried the CPU while soldering it.

Second one came out fine, with sockets. I don't know if the battery
charging circuit works - I didn't try using it. Also when the beeper
comes on, it affects the voltage regulation and the CPU misreads the
pressure sensor. I think that's my fault for using a speaker with 1/2
the impedance specified. A beefier power routing on the PC board
wouldn't hurt, I guess.

I never got it into a box small enough to take up on my paraglider.

Tim

red wrote: